Which of the following is $NOT$ a disaccharide?

The incorrect statement about $Glucose$ is :

$CHO-(CHOH)_4-CH_2OH \xrightarrow{HIO_4} \text{Product}$. Identify the product.

$A$ $D$-aldotetrose on oxidation with concentrated $HNO_3$ resulted in an optically inactive dicarboxylic acid. The structure of the $D$-aldotetrose is:

The letter '$D$' in carbohydrates represents

Identify the reagent that confirms the presence of five $-OH$ groups in glucose.